Impaired associative learning in chronic fatigue syndrome

Patients with chronic fatigue syndrome (CFS) report cognitive difficulties (impaired attention, memory and reasoning). Neuropsychological tests have failed to consistently find cognitive impairments to the degree reported by CFS patients. We tested patients with CFS and sedentary controls in protocols designed to measure sensory reactivity and acquisition of the classically conditioned eyeblink response. Patients with CFS exhibited normal sensitivity and responsivity to acoustic stimuli. However, CFS patients displayed impaired acquisition of the eyeblink response using a delayed-type conditioning paradigm. Sensitivity and responsivity to the airpuff stimulus were normal. In the absence of sensory/motor abnormalities, impaired acquisition of the classically conditioned eyeblink response indicates an associative deficit. These data suggest organic brain dysfunction within a defined neural substrate in CFS patients.

Knowledge, attitudes and practice of epilepsy: experience at a comprehensive rural health services project

Beliefs regarding cause and preference of the treatment modality are important factors influencing any epilepsy programme. Patients own attitudes towards the on-going treatment are equally important in ensuring success of any such programme. The study involved interviews of 80 patients with epilepsy attending a comprehensive rural health services project, and was conducted according to a structured questionnaire. The majority of the patients were well informed regarding the cause of epilepsy, but more than half had tried alternative treatment methods. Many patients had misconceptions regarding the goal of the treatment and the consequences of missing a prescribed drug dose. Surprisingly few patients avoided taking medicines on days of religious fast. It was also noted that most patients depended on free medical supplies from the clinic dispensary, and a small number of patients would stop the medicines if these were not given free of cost. We stress the need to understand patients' concepts about the cause and the treatment of epilepsy, the need to educate them and their families regarding principles of modern medical treatment of epilepsy and most importantly, the need to maintain a regular, uninterrupted supply of free medicines, to improve the effectiveness of similar epilepsy management programmes in the setting of rural India and other developing countries.

Drug-induced gingival enlargements

There are many types of gingival enlargements which vary according to the etiologic factors and pathologic processes that produce them. The most common drug-induced gingival enlargement is associated with Dilantin (phenytoin). Cyclosporin and calcium channel blockers, which are increasingly used for some cardiac diseases, immunosuppression and autoimmune disorders, also cause gingival enlargement. The term "gingival hyperplasia" is an inappropriate term because enlargement is not the result of an increase in the number of cells, but rather an increase in extracellular tissue volume. This paper presents a detailed description of various drug-induced gingival enlargements, including the clinical appearance, microscopic presentation, pathogenic mechanisms and treatment options.

Profile of women undergoing reversal of sterilisation

Two hundred twenty women who were subjected to reversal of female sterilisation over 7 years were analysed. It was found that death of the male child was the strongest reason for seeking a reversal. This was coupled with the parity of these subjects being two or less in 70% instances at the time of primary sterilisation surgery. Nearly 85.9% reversal were sought in the higher age groups clubbed together. This has an adverse bearing on success of reversal surgery as the fertility potential of a woman declines physiologically as age advances.

Capsids are formed in a mutant virus blocked at the maturation site of the UL26 and UL26.5 open reading frames of herpes simplex virus type 1 but are not formed in a null mutant of UL38 (VP19C)

Previously we reported that null mutant viruses of UL19 (VP5) or of UL18 (VP23), essential components of herpes simplex virus type 1 (HSV-1) capsid shells, do not form precursor capsid structures as judged by sedimentation and electron microscope analysis. A goal of the present experiments was to isolate a null mutant virus for the remaining essential component of capsid shells, VP19C, encoded by the UL38 open reading frame (ORF). Furthermore, we wished to determine if a virus altered in the UL26 maturation cleavage site at residues 610 and 611 produced a lethal phenotype. Therefore, we decided to isolate cell lines that encode and express multiple capsid genes. Several cell lines were isolated by transformation of Vero cells and one designated C32 expressed all of the essential capsid proteins. Using this cell line we isolated a null mutant virus in the UL38 ORF and a mutant virus that was altered at residues 610 and 611 of the UL26 and UL26.5 gene products. We found that the null mutant in VP19C did not form a detectable product as judged by sedimentation and electron microscope analyses following infection of nonpermissive cells. The mutant virus altered at the UL26 maturation site resulted in the accumulation of B capsids. Therefore, cleavage at this site was essential for the maturation of B capsids into C capsids. Interestingly, the absence of cleavage at the maturation site was required for the retention of VP24 in the capsid.

The product of the herpes simplex virus type 1 UL25 gene is required for encapsidation but not for cleavage of replicated viral DNA

The herpes simplex virus type 1 (HSV-1) UL25 gene contains a 580-amino-acid open reading frame that codes for an essential protein. Previous studies have shown that the UL25 gene product is a virion component (M. A. Ali et al., Virology 216:278-283, 1996) involved in virus penetration and capsid assembly (C. Addison et al., Virology 138:246-259, 1984). In this study, we describe the isolation of a UL25 mutant (KUL25NS) that was constructed by insertion of an in-frame stop codon in the UL25 open reading frame and propagated on a complementing cell line. Although the mutant was capable of synthesis of viral DNA, it did not form plaques or produce infectious virus in noncomplementing cells. Antibodies specific for the UL25 protein were used to demonstrate that KUL25NS-infected Vero cells did not express the UL25 protein. Western immunoblotting showed that the UL25 protein was associated with purified, wild-type HSV A, B, and C capsids. Transmission electron microscopy indicated that the nucleus of Vero cells infected with KUL25NS contained large numbers of both A and B capsids but no C capsids. Analysis of infected cells by sucrose gradient sedimentation analysis confirmed that the ratio of A to B capsids was elevated in KUL25NS-infected Vero cells. Following restriction enzyme digestion, specific terminal fragments were observed in DNA isolated from KUL25NS-infected Vero cells, indicating that the UL25 gene was not required for cleavage of replicated viral DNA. The latter result was confirmed by pulsed-field gel electrophoresis (PFGE), which showed the presence of genome-size viral DNA in KUL25NS-infected Vero cells. DNase I treatment prior to PFGE demonstrated that monomeric HSV DNA was not packaged in the absence of the UL25 protein. Our results indicate that the product of the UL25 gene is required for packaging but not cleavage of replicated viral DNA.

Paclitaxel (3-hour infusion) followed by carboplatin (24 hours after paclitaxel): a phase II study in advanced non-small cell lung cancer

This phase II study was performed to investigate the efficacy of a 3-hour 225 mg/m2 paclitaxel infusion (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) followed 24 hours later by a 30-minute infusion of carboplatin (dosed to an area under the concentration-time curve of 6) in patients with stage IIIA, IIIB, or IV non-small cell lung cancer. Patients received chemotherapy and were monitored for toxicity, response, quality of life, and survival. Paclitaxel and carboplatin pharmacokinetics were also determined with the first cycle of chemotherapy. Eleven men have been treated to date. Eight were white and three black, with a median age of 65 years. All patients had a performance status of 0 or 1. The regimen was well tolerated, with no deaths or grade 4 toxicities noted. The most common grade 3 toxicity was neutropenia, thrombocytopenia, and parasthesias (observed in <10% of cycles). The overall response rate was 57% (14% complete and 43% partial responses). Quality of life improved in most patients. Physical and emotional well-being improved in 57%, functional well-being in 43%, and social/family well-being in 14% of patients. Pharmacokinetic data are being analyzed by limited sampling technique to predict the paclitaxel area under the concentration-time curve. This unique schedule of paclitaxel and carboplatin is well tolerated and active, and is associated with improvements in various aspects of quality of life.

Subperiosteal osteoid osteoma: radiographic and pathologic manifestations

OBJECTIVE

To demonstrate the radiologic and pathologic manifestations of osteoid osteoma arising beneath the periosteum, on the surface of the bone.

DESIGN

One hundred and sixty osteoid osteomas were seen over a 30-year period. The radiologic, pathologic and operative findings of those that were subperiosteal were reviewed.

PATIENTS

Eleven patients with subperiosteal osteoid osteoma were reviewed. The patients ranged in age from 13 to 36 years with a mean of 24 years. Eight were male and three were female.

RESULTS AND CONCLUSION

Eleven subperiosteal lesions were studied. The reactive periostitis of four lesions was atypical and misleading. Four lesions had features similar to the more common intracortical variety. Three lesions occurring within the joint like other intra-articular lesions were barely seen on plain radiographs. Bone scan and CT scan were virtually diagnostic. The histopathology of these lesions was also atypical though not misleading. In conclusion, subperiosteal osteoid osteoma is a rare lesion with atypical radiographic and histopathologic features. The unusual reactive periostitis seen in several extra-articular cases may suggest other diagnoses.

Impaired color vision in cocaine-withdrawn patients

BACKGROUND

The main reinforcing effect of cocaine happens by altering dopaminergic neurotransmission in the brain reward systems. Dopamine is found in high concentrations in the retina in which it plays an important role in color vision. Therefore, we investigated whether cocaine-dependent patients might have impaired color vision.

METHODS

We compared patients recently withdrawn from cocaine (n = 31) with matched normal controls (n = 31) on 2 color vision tests.

RESULTS

Cocaine-withdrawn patients had significantly higher error scores than matched controls on the Farnsworth-Munsell 100-hue and Lanthony desaturated D-15 color vision tests. Also, 23 of the 31 cocaine-withdrawn patients had blue-yellow color vision losses on the Farnsworth-Munsell 100-hue test compared with 3 controls (P < .001, chi 2 test) and 15 had blue-yellow color vision loss on the Lanthony desaturated D-15 test compared with 2 controls (P < .001, chi 2 test).

CONCLUSIONS

These significantly higher test error scores and blue-yellow color vision losses suggest that color vision is impaired in cocaine-withdrawn patients. Color vision testing may be useful in future studies of cocaine-dependent patients.

Epiphyseal extension of a unicameral bone cyst

Epiphyseal extension of a unicameral bone cyst is rare. We report a case of a 13-year-old boy with three pathological fractures through a unicameral bone cyst with epiphyseal involvement in the proximal humerus. These lesions initially tends to expand the humeral epiphysis laterally and progress medially. They also commonly cause a slip of the epiphysis in a medical direction. They also have a greater association with growth retardation and lesser degree of recurrence than their metaphyseal counterpart.

Gains from cataract surgery: visual function and quality of life

AIMS

To describe the impact of cataract surgery in terms of visual function (functioning in everyday life with respect to vision dependent activities) and health related quality of life.

METHODS

An observational, longitudinal study of patients undergoing cataract surgery was carried out at three district general hospitals in outer London districts of North Thames Region with follow up at 4 and 12 months postoperatively for a clinical assessment and a standardised administered interview. Patients were admitted for surgery to the first eye for age-related cataract between 1 May 1993 and 31 August 1994. Visual functioning was assessed by the VF-14, health related quality of life was assessed by the sickness impact profile (SIP), and vision related quality of life was assessed by VR-SIP (a modification of the generic SIP).

RESULTS

Significant gains in all the outcome measures were demonstrated at 4 months postoperatively. No significant change (gain or loss) was observed between 4 and 12 months after surgery to the first eye. Postoperatively, the mean visual function (VF-14) scores, and health related (SIP) and vision related (VR-SIP) quality of life scores, indicated less reported trouble with vision dependent activities and better perceived quality of life, respectively. The average gains in visual function and quality of life (health and vision related) were apparent in groups with good visual outcome and poor visual outcome. Significant additional gains were seen at 1 year in patients who had second eye surgery in the interval between the postoperative assessments.

CONCLUSIONS

Gains in visual functioning and quality of life (health and vision related) have been demonstrated following cataract surgery. These gains were sustained at 1 year after surgery to the first eye, with additional gains being conferred if second eye surgery had been performed. Assessment of the outcomes of cataract surgery by clinical indicators alone may underestimate the overall benefits of surgery, particularly in patients with poor visual outcome.

The reliability of analysis of intraoperative frozen sections for identifying active infection during revision hip or knee arthroplasty

A prospective study was performed to determine the reliability of analysis of intraoperative frozen sections for the identification of infection during 175 consecutive revision total joint arthroplasties (142 hip and thirty-three knee). The mean interval between the primary and the revision arthroplasty was 7.3 years (range, three months to twenty-three years). To reduce selections bias, tissue was obtained for frozen sections during all revisions in patients who did not have active drainage from the wound or a sinus tract. Of the 175 patients, twenty-three had at least five polymorphonuclear leukocytes per high-power field on analysis of the frozen sections and were considered to have an infection. Of these twenty-three, five had five to nine polymorphonuclear leukocytes per high-power field and eighteen had at least ten polymorphonuclear leukocytes per high-power field. The frozen sections for the remaining 152 patients were considered negative. On the basis of cultures of specimens obtained at the time of the revision operation, nineteen of the 175 patients were considered to have an infection. Of the 152 patients who had negative frozen sections, three were considered to have an infection on the basis of the results of the final cultures. Of the twenty-three patients who had positive frozen sections, sixteen were considered to have an infection on the basis of the results of the final cultures; all sixteen had frozen sections that had demonstrated at least ten polymorphonuclear leukocytes per high-power field. The sensitivity and specificity of the frozen sections were similar regardless of whether an index of five or ten polymorphonuclear leukocytes per high-power field was used. Analysis of the frozen sections had a sensitivity of 84 per cent for both indices, whereas the specificity was 96 per cent when the index was five polymorphonuclear leukocytes and 99 per cent when it was ten polymorphonuclear leukocytes. However, the positive predictive value of the frozen sections increased significantly (p < 0.05), from 70 to 89 per cent, when the index increased from five to ten polymorphonuclear leukocytes per high-power field. The negative predictive value of the frozen sections was 98 per cent for both indices. The current study suggests that it is valuable to obtain tissue for intraoperative frozen sections during revision hip and knee arthroplasty. At least ten polymorphonuclear leukocytes per high-power field was predictive of infection, while five to nine polymorphonuclear leukocytes per high-power field was not necessarily consistent with infection. Less than five polymorphonuclear leukocytes per high-power field reliably indicated the absence of infection.

Epidemiology and implications of ocular trauma admitted to hospital in Scotland

OBJECTIVES

To describe the current epidemiology of serious ocular trauma which necessitates admission to hospital so that health and safety strategies for the prevention of ocular injuries and their role within the national health strategy, The Health of the Nation, can be better informed.

DESIGN

A prospective observational study of all patients with ocular trauma admitted to hospital under the care of a consultant ophthalmologist between 1 November 1991 and 31 October 1992.

SETTING

All ophthalmic department in Scotland.

SUBJECTS

All patients with ocular trauma admitted to hospital in Scotland. The population of Scotland represented the population at risk of injury.

MEASURES AND MAIN RESULTS

Measures included the type and cause of injury, the place where it occurred, and awareness of risk and safety. All ophthalmic departments in Scotland participated and 428 admissions were reported. The home was the most common place for a serious injury to occur (30.2%), followed by the workplace (19.6%) and a sports or leisure facility (15.8%). The home was the single most frequent place of injury for the 0-15 year and 65 year and over age groups. Tools or machinery, either at home (13.9%) or at work (10.3%), were collectively (24.2%) the most frequent cause of injury, followed by assault (21.8%) and sports-related activities (12.5%). The most frequent type of injury was a blunt injury (54.4%). Six per cent (n = 25) of all injuries were bilateral. Only 13.2% of patients were aware of any risk of injury, with 5.6% aware of any risk at home. When applicable, protective eye wear was only available to 48.6% of patients and only 19.4% of these used it.

CONCLUSION

Serious ocular trauma frequently occurs at home and the young and the elderly are particularly at risk. This represents a significant change in the epidemiology of serious ocular trauma and has important implications for prevention. Health and safety strategies specifically aimed at preventing eye injury should now include the home as a high risk environment in addition to the work-place and sports/leisure facilities. The target groups for accident prevention in The Health of the Nation strategy include those at risk of serious ocular trauma with potentially sight threatening sequelae. Those involved in implementing the national accident prevention strategy should be aware of this, for in this process it is possible that some serious eye injuries may also be prevented.

Intracortical and subperiosteal aneurysmal bone cysts: a report of three cases

Aneurysmal bone cyst of the long bones in a purely intracortical or subperiosteal location is unusual. Three such cases are reported, and the radiographic and pathologic differential diagnoses are discussed. Those subperiosteal or intracortical aneurysmal bone cysts with radiographic features similar to the intramedullary variety should suggest the same diagnosis. However, the radiographic features may be less specific, so that a diagnosis of aneurysmal bone cyst must be entertained when considering a subperiosteal or intracortical lytic lesion.

Incidence of cases of ocular trauma admitted to hospital and incidence of blinding outcome

AIMS

To provide epidemiological data on the current burden of serious eye injuries utilising the hospital eye service, to inform the planning and provision of eye health care, and health and safety strategies for the prevention of ocular injuries.

METHODS

A prospective observational study was carried out of all patients with ocular trauma admitted to hospitals in Scotland, under the care of a consultant ophthalmologist, during a 1 year period. The population of Scotland represented the population at risk of injury. Visual outcome (Snellen visual acuity in the injured eye) was measured at the time of final discharge from ophthalmic care and at follow up.

RESULTS

All ophthalmic departments in Scotland participated and a total of 415 residents of Scotland were admitted. The 1 year cumulative incidence of ocular trauma necessitating admission to hospital is estimated to be 8.14 per 100 000 population (95% CI 7.38 to 8.97). Some 13.2% (n = 26/197) of patients discharged from follow up had a poor visual outcome with a visual acuity less than 6/12 in the injured eye. Some 10.7% (21/197) patients at this time had a blinding outcome in the injured eye (visual acuity less than 6/60). No patient was registered blind or partially sighted during the study period. The home was the single most frequent place for blinding injuries to occur (52%, n = 11/21), followed by the workplace 24% (n = 5/21). The 1 year cumulative incidence of blinding outcome from serious ocular trauma is estimated to be 0.41 per 100 000 population per year (95% CI 0.26 to 0.64).

CONCLUSION

The current burden of serious ocular trauma presenting to the hospital eye service has been quantified from this population based study, and for the first time, a direct estimate of the incidence of the subsequent blinding outcome from these injuries has been provided. Ocular trauma remains an important cause of avoidable and, predominantly, monocular visual morbidity (visual impairment and blindness), with over half of the blinding injuries now occurring in the home. Health education and safety strategies should now consider targeting the home for the prevention of the serious eye injuries in addition to the traditional work, sports, and leisure environments and their related activities.

Molecular interactions between the HSV-1 capsid proteins as measured by the yeast two-hybrid system

HSV-1 B capsids are composed of seven major proteins, designated VP5, VP19C, 21, 22a, VP23, VP24, and VP26. VP indicates that the capsid protein is also a component of the infectious virion. Capsid proteins 21, 22a, and VP24 are specified by a single open reading frame (UL26) that encodes 635 amino acids. An objective of the work in our laboratory is to identify and map interactions among and between capsid proteins. In the present studies we employed the yeast GAL4 two-hybrid system developed by Fields and his colleagues (Nature 240, 245-246 (1989)) for this purpose. DNA corresponding to the capsid open reading frames was derived as a PCR product and fused to sequences of the GAL4 activation and DNA binding domains. Using this system each of the capsid proteins has been tested for interactions with all of the other capsid proteins. Three interactions have been identified: a relatively strong self-interaction between 22a molecules (residues 307-635 of UL26), bimolecular interactions between 22a and VP5, and another between VP19C and VP23. The interactions were detected by the expression of beta-galactosidase enzyme activity, and yielded 289, 86, and 63 units of enzyme activity, respectively. For the 22a self-interaction, elimination of residues 611-635 resulted in an approximately twofold decrease in enzyme activity. The C-terminal 25 amino acids of 22a were also essential for the bimolecular interaction between 22a and VP5.

Sarcoma in association with bone infarcts. Report of five cases

Sarcoma associated with bone infarct is rare, and only 41 well-documented cases have been published. We describe five additional patients, three women and two men, aged 39 to 57 years. The tumors involved the femur (three patients), tibia (one patient), and humerus (one patient). In three patients, the infarcts were idiopathic. Radiologic evidence of malignancy was found in all patients, and bone infarcts were suspected in four. Four of the patients had malignant fibrous histiocytoma and one an osteosarcoma. Histologically, bone infarcts were seen in all patients, but in three they were mostly replaced by tumor. Portions of intact infarcts were seen adjacent to the tumor, indicating that they had preceded the development of the sarcoma. No hypercellular or atypical reparative tissue was found in the infarcted bones or in three additional uncomplicated infarcts studied from the same patients. The pathogenesis of sarcoma arising in bone infarct is unknown. The prognosis is poor; four of our five patients died within 2 years.

How should we investigate women with postmenopausal bleeding?

OBJECTIVE

To evaluate the optimum method(s) of investigating women with postmenopausal bleeding.

DESIGN

Prospective study of 76 postmenopausal women.

SETTING

Teaching Hospital. Interventions. All women had pipelle endometrial biopsy in outpatient clinic. Prior to inpatient hysteroscopy and uterine curettage, each woman had pelvic ultrasonography to measure the endometrial thickness and to exclude ovarian pathology.

RESULTS

Pipelle biopsy was successful in 70% of cases and has a sensitivity of 70%. Hysteroscopy has superior diagnostic capabilities allowing direct visualisation of the endometrial cavity with directed biopsies. Endometrial thickness of > 5 mm used as an indicator of endometrial pathology compared to uterine curettage has a sensitivity of 83%, a specificity of 77%, and a positive predictive value of 54%. Ultrasound also detected five ovarian tumors, two of which were malignant and three missed by pelvic examination alone.

CONCLUSIONS

We recommend the routine use of pelvic ultrasonography in all women with postmenopausal bleeding as it is an invaluable diagnostic tool in excluding ovarian pathology. In addition, sampling of the endometrial cavity, preferably with outpatient hysteroscopy, is mandatory for histological diagnosis. Overall, the combination of ultrasound and outpatient endometrial sampling would spare hospital admission for at least 60% of women with postmenopausal bleeding.

Combined third-generation implantable cardioverter defibrillator with permanent unipolar pacemakers: preliminary observations

As implantable cardioverter defibrillators (ICDs) are strictly contraindicated in the presence of unipolar pacemakers, currently available options in patients having such chronic pacing systems include: abandoning the implanted pacemaker and selecting an ICD with ventricular demand (VVI) pacing; or replacing the chronic (dual chamber) unipolar pacing system with a dedicated bipolar version prior to ICD implantation. In three patients with previously implanted unipolar pacemakers, we challenged the premise that all ICD systems are incompatible by combining with a third-generation transvenous ICD system (Medtronic 7217B PCD) incorporating true bipolar sensing, a self-limiting auto-adjusting sensitivity, and a tolerant VF detection algorithm. The potential for pacemaker-ICD interaction was minimized by separating the tip of the ICDs transvenous right ventricular pace/sense-defibrillation coil lead from that of the chronic pacemaker lead by > or = 2-3 cm, and by performing "worst case" intraoperative testing. Although ICD double-counting of the dual chamber pacemaker's atrial and ventricular pacing spikes could be provoked at extreme high output settings, it did not occur at clinically appropriate settings. More importantly, continuous high output asynchronous pacing during ventricular fibrillation (VF) did not interfere with ICD detection. During a mean follow-up period of 18 months, one patient has had VF appropriately terminated by the ICD. In the remaining two patients, proper VF detection and ICD function was reassessed at 3 months and/or at 1 year during noninvasive testing.

CONCLUSION

These preliminary findings demonstrate that this transvenous ICD system's VF sensing and detection features combined with careful implant technique, rigorous "worst case" testing for possible pacemaker-ICD interaction with regular follow-up, may permit implantation of this ICD system in patients with chronic unipolar pacing systems. Further studies are needed to validate the long-term clinical safety of this promising revised approach to a currently contraindicated device combination.

Inhibition of myeloma cell growth by dexamethasone and all-trans retinoic acid: synergy through modulation of interleukin-6 autocrine loop at multiple sites

Interleukin-6 (IL-6)/IL-6 receptor (IL-6R) plays a major role in autocrine/paracrine growth regulation of myeloma cells. We investigated the effect of dexamethasone and all-trans retinoic acid, previously shown to modulate IL-6/IL-6R, on the in vitro growth of a human myeloma cell line, OPM-2. Both agents inhibited the clonogenic growth and 3H-thymidine incorporation in a concentration-dependent fashion. Isobologram and median effect analysis showed a strong synergy between these two agents with a combination index in the range of 0.2 to 0.6. Both agents decreased the labeling index and the cell fraction in S and G2/M phases, suggesting a block in G1-S phase transition. The clonogenic growth was stimulated by exogenous IL-6 and was inhibited by monoclonal antibody to IL-6, suggesting an autocrine function of IL-6. The effect of dexamethasone but not all-trans retinoic acid was completely reversed by exogenous IL-6. Dexamethasone increased, while all-trans retinoic acid reduced, IL-6R but not gp130 mRNA expression. Their combination caused a net reduction in IL-6R mRNA. Cellular IL-6R density was altered correspondingly without changes in the binding affinity. IL-6 mRNA expression was reduced by dexamethasone and the combination, but was not affected by retinoic acid alone. However, IL-6 secretion into culture supernatant was abolished by both agents. A survey of 4 additional human myeloma cells showed that 1 was sensitive to both, 1 was sensitive to one agent only, and 2 were resistant to both. The study demonstrates the possibility of regulating myeloma cell growth through modulation of IL-6/IL-6R autocrine/paracrine loop and the principle of achieving a synergistic effect by blocking this loop at multiple sites.

The role of intraoperative frozen sections in revision total joint arthroplasty

We performed a retrospective analysis of thirty-three consecutive total hip and knee (twenty-three hip and ten knee) revision arthroplasties during which intraoperative frozen sections were analyzed. Data for the study were collected by means of a review of the charts, radiographic analysis, and evaluation of both frozen and permanent histological sections. The frozen sections, of periprosthetic tissue at the bone-cement interface or the pseudocapsule, were considered positive for active infection if there were more than five polymorphonuclear leukocytes per high-power field in at least five distinct microscopic fields. All patients were available for follow-up, at an average of thirty-six months (range, seventeen to seventy-nine months) after the initial revision operation. The frozen sections from ten patients were positive for infection, and those from twenty-three patients were negative. Comparison of the results of the analyses of the frozen sections (both positive and negative) with those of the analyses of the permanent histological sections of similar tissue showed a correlation of 100 per cent (sensitivity, 1.00; specificity, 1.00; and accuracy, 1.00). Nine patients had positive intraoperative cultures, and all of them had positive frozen sections (sensitivity, 1.00). Of the twenty-four patients who had negative intraoperative cultures, twenty-three had negative frozen sections (specificity, 0.96). Of the nine patients who had positive intraoperative cultures, only two were found to have infection on intraoperative gram-staining. The surgeon's operative assessment regarding the presence of infection, compared with the final pathological diagnosis, demonstrated a sensitivity of 0.70, a specificity of 0.87, and an accuracy of 0.82. All ten patients who had positive frozen sections were managed with excision arthroplasty; six of them subsequently had reimplantation, and the excision was the definitive procedure in the remaining four. One patient who had had a delayed reimplantation had a secondary skin slough and eventually was managed with an arthrodesis of the knee. In the group that had negative frozen sections, eighteen patients had a primary exchange revision arthroplasty and five had a delayed reimplantation. At the time of follow-up, one patient who had had a delayed reimplantation had radiographic loosening of the femoral component and was asymptomatic. One patient who had had a primary exchange arthroplasty was managed with a second revision because of aseptic loosening. There was no clinical recurrence of infection in any patient. The data indicate that analysis of frozen sections of periprosthetic tissue is a reliable predictor of the presence of active infection during revision joint arthroplasty. We recommend its use to differentiate aseptic from septic loosening.